Since 1995, Europe has been going through a piecemeal process of becoming a continent without internal borders. On March 26 of that year the Schengen Agreement took effect, implementing a visa-free area between the five original signatory states: Belgium, France, Luxembourg, Germany and the Netherlands.
Since then, the Schengen Area has grown to include all other members of the European Union with the exception of Britain and Ireland - which chose not to join. Iceland, Norway and Switzerland are also part of the zone.
With the exception of random police checks at airports, train stations and on highways, border controls between Schengen states no longer exist. People and goods can freely cross the countries' borders, eliminating hassles both for travelers and for businesses.
Check out the articles below for a closer look at how Schengen has changed Europe.